Vehicular drift indicator-speedometer

ABSTRACT

A vehicular drift indicator - speedometer for measuring either vehicular drift or speed, or the rate of flow of a medium. Invention utilises a transducer in form of an impeller mounted in a circular aperture and having on its axis a cam member used to drive a pair of spring contacts. Said contacts connect and disconnect bias supply to a transistor which conducts accordingly producing square wave pulses. Said pulses are driving circuitry producing a short pulse of constant duration per each drive pulse. Said short pulses of constant duration are then integrated and used to drive an indicating meter. In all cases a differential pressure developed between ends of said aperture drives a certain amount of medium through it, thus medium drives said impeller and circuitry producing appropriate indication. When used as a drift indicator said impeller and switch are mounted in said aperture being perpendicular to the direction of the vehicular travel, and being part of the vehicular body or affixed to it as a separate body. When used as a speedometer aperture is aligned with the vehicular direction of travel, the rest is same as above. When used as a flow rate indicator, arrangement is such that medium under consideration is moving through the aperture driving an impeller and producing indication as before.

Unite States Patent 1191 Milovancevic 1451 Sept. 4, 1973 l VEHICULARDRIFT INDICATOR-SPEEDOMETER Slavko Milovancevic, P. O. Box 402,Torrance, Calif. 90508 [22] Filed: Apr. 1, 1971 [21] Appl. No.: 130,078

[76] Inventor:

52 U.S.Cl. 73/187 51 int. Cl ..G0lc21/10 58 Field of Search 73/187, 186,184,

[56] References Cited UNITED STATES PATENTS 3/1969 Mergler 73/23l R4/1969 Althouse et al 73/23l R Primary Examiner-Donald O. Woodiel [57]ABSTRACT A vehicular drift indicator-speedometer for measuring eithervehicular drift or speed, or the rate of flow of a medium. Inventionutilizes a transducer in form of an impeller mounted in a circularaperture and having on its axis a cam member used to drive a pair ofspring contacts. Said contacts connect and disconnect bias supply to atransistor which conducts accordingly producing square wave pulses. Saidpulses are driving circuitry producing a short pulse of constantduration per each drive pulse. Said short pulses of constant durationare then integrated and used to drive an indicating meter.

In all cases a differential pressure developed between ends of saidaperture drives a certain amount of medium through it, thus mediumdrives said impeller and circuitry producing appropriate indication.

When used as a drift indicator said impeller and switch are mounted insaid aperture being perpendicular to the direction of the vehiculartravel, and being part of the vehicular body or affixed to it as aseparate body.

When used as a speedometer aperture is aligned with the vehiculardirection of travel, the rest is same as above.

When used as a flow rate indicator, arrangement is such that mediumunder consideration is moving through the aperture driving an impellerand producing indication as before.

5 Claims, 4 Drawing Fig ures Patented Sept. 4, 1973- 3,756,077

I NVEN TOR.

VEHICULAR DRIFT INDICATOR-SPEEDOMETER BACKGROUND OF THE INVENTION 1.Field of the invention The present invention relates generally tomeasuring instruments and particularly to air and water navigationaldrift and velocity measuring instruments.

2. Description of the prior art As far as known to applicant there is noknown instrument of this type described or used for vehicular drift orvelocity measurements.

DESCRIPTION OF THE DRAWINGS F161 is a combined circuit and block diagramshowing all essentials of square wave pulse producing,processing,andindication as function of number of openings and closings of contactsdesignated 5.

FIG.2 shows two pairs of mechanical contacts activated by propelerrotation.

FIG.3 shows an aerodynamically shaped body with a transversal hole wherepropeler and switches are located,medium flow lines,medium pressurefront,and vectorial diagram of involved velocities as related tovehicular drift measurement.

FIGA shows an aerodynamically shaped body with an axial hole wheretransducer from FIG.2 is located,when speed or flow rate is beingmeasured.

DETAILED DESCRIPTION OF OPERATION The objectives of this invention wereTo find an instrument for vehicular drift,speed and/or flow rate ofmedium measurement insensitive to ambient, i.e., medium temperaturechanges,sensitive to pressure changes, mechanically robust,simple andinexpensive- ,and yet accurate enough.

Referring now to FIG.1,vehicular drift indicator speedometer of presentinvention includes a regulated d-c voltage source generally designated1,a power switch designated 2,three biasing resistors designated 3,4,and 8,spring contacts 5,two small capacitors 6 and 7,a transistor ofn-p-n type designated 9,a differential network generally designated 10,apulse separation circuit generally designated l1,a square wave formingnetwork generally designated 12,a square wave amplifier generallydesignated 13,a blocking diode designated I4,a storage capacitordesignated 15, two current limiting resistors designated 16 and 18,apushbutton switch designated 17,a calibration rheostat 19,and amicroampermeter or similar type indicator designated 20.0peration is asfollows.When switch 2 is closed circuit is supplied with power fromsource l,biasing resistors 3 and 4 form a voltage divider chargingcapacitors 6 and 7.Transistor 9 is in off state.The moment contacts 5close capacitor 6 discharges through them.At same time transistor 9 willbe forward biased and start conducting heavily.Capacitor 7 will slowdown turn on of transistor 9 making sure that spikes possibly producedby bouncing of contacts 5 during closing will not be transferred tocircuit 10.0nce on transistor 9 will enter saturation or near saturationregion conducting heavy current to produce voltage drop across resistor8 nearly equal to supply voltage.W- hen contacts 5 open capacitor 7 willdischarge through capacitor 6 which will be charged also throughtransistor 9,th us keeping transistor 9 for time long enough to assurethat contacts 5 are definitely open and prevent possible short spikesproduction due to bouncing during its opening.Transistor 9 will thenstop conducting after a short delay,thus voltage across resistor 6 willdrop to zero.Concentrating our attention to resistor 8 during describedprocess one will find a voltage rising from zero to nearly supplyvoltage,remain at that value as long as contacts 5 are closed,and aftera short delay will drop fast to zero representing thus a positive goingvoltage pulse of rectangular type or rather close to it in form.Thissame position rectangular voltage pulse is applied to differentiatingnetwork designated 10,which will produce a positive going spike acrossits output during rectangular pulse rise time,no output during flatportion of the pulse,and a negative going spike during rectangular pulsefall time,thus differentiating the rectangular pulse.A singlerectangular pulse is then transformed into one positive and one negativegoing spike.- From FIG.2 is obvious that each propeller rotation willproduce two rectangular pulses or in other words each propeler rotationwill produce two positive and two negative going spikes atdifferentiator l0 output.This- ,of course,repeats for each rotation ofthe propeler.- Separation network 11 then passes only either positive ornegative type spikes to square wave generator 12 which in turn producesa short duration rectangular pulses of short duration shorter thanshortest one produced by the transistor 9 one pulse for each spikeappearing at its input,thus two pulses per each rotation of the propelerin FIG.2.These pulses of constant duration are then amplified by squarewave amplifier 13 and fed through blocking diode 14 to storage capacitor15.From diode 14 position is obvious that pulses coming from theamplifier 13 must be positive in order to reach and charge positivelythe capacitor 15.Faster propeller rotates more pulses are produced,morecapacitor 15 will be charged positively the higher voltage across itwill be developed.This voltage drives a current through current limitingresistors 16 and 18, calibarting rheostat 19 and the meter 20 whichindicates how high that voltage across 15 is.Note also that timeconstant formed by capacitor l5,resistors 16 and 18,calibrating rheostatl9,and internal resistance of indicator 20 must be much longer than theduration of the longest repetition time between pulses produced bytransistor 9.Momentary push-button switch 17 serves for fast dischargeof capacitor 15 to allow momentary reading on meter 20 or if made aslocking type to protect meter from possible overloading.

Referring now to FIG.2 vehicular drift indicatorspeedometer of thepresent invention includes elements 21 through 32 only essential ones toshow principle of operation.Operation of this device is as folows Due tomedium stream around propeller 21 it will rotate with an angular speeddependent on the stream speed,propeller axle 22 equally so and a profile24 at the end of the aXIeAXiaI-radial type bearing 23 takes all axialand radial forces and keeps axle and propeller in proper positionrelative to stream. During its rotation profile 24 depresses springs 25and 28 causing closing contacts 26 and 27 twice per each rotation andtwice to open as well.Springs 25 and 28 are connected in parallel bywires 29 and 30 to increase relability of operation,while conductors 31and 32 serve as connecting wires to circuit elements 3,4,6,7,and 9 inFIG.1.This way medium flow is transduced in closing and opening ofcontacts 26 and 27 represented by switch 5 in FlG.l,thus affectscircuitry in FlG.1 as described before.

Referring to FlG.3 vehicular drift indicator speedometer of the presentinvention includes an aerodynamically shaped body 33 with a circularhole 34.Body 33 is part of the vehicle itself or conveniently affixed toit so that its hole takes a position perpendicular to vehiculardirection of motion.lnside the hole 34 is then placed transducer fromFIG.2,while connecting wires 31 and 32 are fed to circuitry.

To give a better idea on principle used for operation some vectors areused like vector v, representing medium velocity,vector v, vehicularvelocity in the intended direction of motion,vector v vehicular driftingvelocity due to medium flow,and v resulting vehicular velocity.Note thatv,, and v,,,,, are not equal,that v,,, is larger,thus there will be adifference in pressure on both sides of vehicle and body 33 as wellDueto this difference in pressure medium will flow through the hole 34activating device in FIG.2.

Referring to FIGA it is obvious that similar arrangement can be used tomeasure vehicular speed or the flow rate through the hole 36 in theaerodynamically shaped body 35.

This is only one of many possible solutions which all fall within thescope and essence of this invention.

I claim 1. An Indicator for indicating the velocity of a vehiclerelative to a medium in which the vehicle is travelling and comprizingan impeller rotatably mounted on said vehicle and in communications withsaid medium,

a cam member attached to said impeller and rotatable therewith,

switch contact means mounted opposite said cam member, said switchcontact means being actuated by said cam member in accordance with therotation of the impeller,

an electrical power source for providing voltage for operation ofelectrical circuitry through a common lead and a power switch whoseother terminal is connected to the other lead supplying power to:

a series connection of two resistors, one being connected with one endto said common terminal, second resistor being connected to said otherlead,

an n-p-n type transistor having emitter,base and collector electrodes,said collector electrode being connected to said other lead, emitterelectrode being connected to a resistor whose other end is connected tosaid common terminal,

a capacitor connected between the base electrode of said transistor andthe interconnection of said two in series connected resistors saidswitch contact means being connected across said capacitor (as shown inFIG.1) providing drive current for said transistor whenever said switchcontact means is closed, said drive current causes conduction of saidtransistor, thus producing a rectangular voltage pulse across saidresistor,

a differentiator having its input lead connected to interconnection ofsaid resistor and said transistor for accepting said rectangular voltagepulse across said resistor,having its common lead connected to saidcommon lead, and its output lead connected to a pulse separation networkinput lead, allowing passage of differentiating pulses of desiredpolarity (differentiating pulses representing a positive going and anegative going sharp pulse produced by differentiator per eachrectangular voltage pulse), and having its common lead connected to saidcommon lead, and its output lead connected to the input lead of a meansfor producing rectangular pulses of same amplitude and constant durationand same in number as the rectangular pulses produced by saidtransistor, having its common lead connected to said common lead, itssupply lead connected to said other lead to accept electric power, andits output lead connected to the input lead of a square wave amplifierhaving its common lead connected to said common lead, its supply lead tosaid other lead to receive electric power for operation and its outputlead connected to the anode electrode of a diode having its cathodeconnected to an integrating capacitor having its other plate connectedto said common lead, and used to integrate said pulses of constantduration,

first current limiting resistor tied up to the interconnection of saiddiode and said capacitor, and its other end connected to a pushbuttonswitch to allow fast discharge of said integrating capacitor throughsaid first current limiting resistor and another current limitingresistor connected to interconnection of said first current limitingresistor and said pushbutton switch,

a calibrating rheostat connected to said common lead and its other endto the other end of said second current limiting resistor and a readoutmeans for providing a readout of the output of said integrating meansand having its other lead connected to said common lead.

2. The indicator of claim 1 wherein the drift of the vehicle isindicated and further comprising a duct supported on said vehicle so itis exposed to the medium surrounding the vehicle, said duct having anaperture facing in a direction substantially normal to principaldirection of travel of said vehicle, said aperture providingcommunication of said medium to the inside of said duct, said impellerbeing rotatably mounted within the casing, the rotation axis of theimpeller being substantially normal to the principal direction ofvehicular travel, said impeller being rotatably driven in accordancewith the velocity of the medium entering the duct.

3. The indicator of claim 1 wherein the speed of the vehicle isindicated and further comprising a duct supported on said vehicle so itis exposed to the medium surrounding the vehicle, said duct having anaperture facing in substantially same direction as the principaldirection of travel of said vehicle, said aperture providingcommunication of said medium to the inside of said duct, the rotationaxis of said impeller being in substantially same direction as theprincipaldirection of vehicle travel, said impeller being rotatablydriven in accordance with the velocity of the medium enterring the duct.

4. The indicator of claim 1 wherein said switch contact means comprisestwo pairs of switch contacts and separate resilient arm means forsupporting each of the contact pairs, said arm means being positioned inthe rotation path of the cam member.

5. An indicator for indicating the rate of flow of a medium through anaxial aperture of a cylindrical body and comprising a rotation axissupported by said cylindrical body and being coaxial with it and furthercomprising an impeller rotatably mounted on said cylindrical body and incommunications with said medium,

a cam member attached to said impeller and rotatable therewith,

switch contact means mounted opposite said cam member, said switchcontact means being actuated by said cam member in accordance with therotation of the impeller,

an electrical power source for providing voltage for operation ofelectrical circuitry through a common lead and through a power switchwhose other terminal is connected to the other lead supplying power to aseries connection of two resistors, one being connected with one end tosaid common terminal, second resistor being connected to said otherlead,

an n-p-n transistor having emitter, base and collector electrodes, saidcollector electrode being connected to said other lead, said emitterelectrode being connect to a resistor whose other end is connected tosaid common terminal,

a capacitor connected between the base electrode of said transistor andthe interconnection of said two in series connected resistors saidswitch contact means being connected across said capacitor (as shown inF161) providing drive current for said transistor whenever said switchcontact means is closed, said drive current causes conduction of saidtransistor, thus producing a rectangular voltage pulses across saidresistor,

a differentiator having its input lead connected to interconnection ofsaid resistor and said transistor for accepting said rectangular voltagepulses across said resistor, having its common lead connected to saidcommon lead, and its output lead connected to a pulse separation networkinput lead, allowing passage of differentiating pulses of desiredpolarity (differentiating pulses representing a positve going and anegative going sharp pulse produced by differentiator per eachrectangular voltage pulse), and having its common lead connected to saidcommon lead, and its output lead connected to the input lead of a meansfor producing rectangular pulses of same amplitude and constant durationand same in number as the rectangular pulses produced by saidtransistor, having its common lead connected to said common lead, itssupply lead connected to said other lead to accept electric power, andits output lead connected to the input lead of a square wave amplifierhaving its common lead connected to said common lead, its supply lead tosaid other lead to receive electric power for operation and its outputlead connected to the anode electrode of a diode having its cathodeconnected to an integrating capacitor having its other plate connectedto said common lead and used to integrate said pulses of constantduration,

first current limiting resistor tied up to the interconnection of saiddiode and said capacitor, and its other end connected to a pushbuttonswitch to allow fast discharge of said integrating capacitor throughsaid first current limiting resistor and another current limitingresistor connected to interconnection of said first current limitingresistor and said pushbutton switch,

a calibrating rheostat connected to said common lead and its other endto the other end of said second current limiting resistor and a readoutmeans for providing a readout of the output of said integrating meansand having its other lead connected to said common lead.

1. An Indicator for indicating the velocity of a vehicle relative to amedium in which the vehicle is travelling, and comprizing: an impellerrotatably mounted on said vehicle and in communications with saidmedium, a cam member attached to said impeller and rotatable therewith,switch contact means mounted opposite said cam member, said switchcontact means being actuated by said cam member in accordance with therotation of the impeller, an electrical power source for providingvoltage for operation of electrical circuitry through a common lead anda power switch whose other terminal is connected to the other leadsupplying power to: a series connection of two resistors, one beingconnected with one end to said common terminal, second resistor beingconnected to said other lead, an n-p-n type transistor having emitter,base and collector electrodes, said collector electrode being connectedto said other lead, emitter electrode being connected to a resistorwhose other end is connected to said common terminal, a capacitorconnected between the base electrode of said transistor and theinterconnection of said two in series connected resistors; said switchcontact means being connected across said capacitor (as shown in FIG. 1)providing drive current for said transistor whenever said switch contactmeans is closed, said drive current causes conduction of saidtransistor, thus producing a rectangular voltage pulse across saidresistor, a differentiator having its input lead connected tointerconnection of said resistor and said transistor for accepting saidrectangular voltage pulse across said resistor, having its common leadconnected to said common lead, and its output lead connected to a pulseseparation network input lead, allowing passage of differentiatingpulses of desired polarity (differentiating pulses representing apositive going and a negative going sharp pulse produced bydifferentiator per each rectangular voltage pulse), and having itscommon lead connected to said common lead, and its output lead connectedto the input lead of a means for producing rEctangular pulses of sameamplitude and constant duration and same in number as the rectangularpulses produced by said transistor, having its common lead connected tosaid common lead, its supply lead connected to said other lead to acceptelectric power, and its output lead connected to the input lead of asquare wave amplifier having its common lead connected to said commonlead, its supply lead to said other lead to receive electric power foroperation and its output lead connected to the anode electrode of a:diode having its cathode connected to an integrating capacitor havingits other plate connected to said common lead, and used to integratesaid pulses of constant duration, first current limiting resistor tiedup to the interconnection of said diode and said capacitor, and itsother end connected to a pushbutton switch to allow fast discharge ofsaid integrating capacitor through said first current limiting resistorand another current limiting resistor connected to interconnection ofsaid first current limiting resistor and said pushbutton switch, acalibrating rheostat connected to said common lead and its other end tothe other end of said second current limiting resistor and a readoutmeans for providing a readout of the output of said integrating meansand having its other lead connected to said common lead.
 2. Theindicator of claim 1 wherein the drift of the vehicle is indicated andfurther comprising: a duct supported on said vehicle so it is exposed tothe medium surrounding the vehicle, said duct having an aperture facingin a direction substantially normal to principal direction of travel ofsaid vehicle, said aperture providing communication of said medium tothe inside of said duct, said impeller being rotatably mounted withinthe casing, the rotation axis of the impeller being substantially normalto the principal direction of vehicular travel, said impeller beingrotatably driven in accordance with the velocity of the medium enteringthe duct.
 3. The indicator of claim 1 wherein the speed of the vehicleis indicated and further comprising: a duct supported on said vehicle soit is exposed to the medium surrounding the vehicle, said duct having anaperture facing in substantially same direction as the principaldirection of travel of said vehicle, said aperture providingcommunication of said medium to the inside of said duct, the rotationaxis of said impeller being in substantially same direction as theprincipaldirection of vehicle travel, said impeller being rotatablydriven in accordance with the velocity of the medium enterring the duct.4. The indicator of claim 1 wherein said switch contact means comprisestwo pairs of switch contacts and separate resilient arm means forsupporting each of the contact pairs, said arm means being positioned inthe rotation path of the cam member.
 5. An indicator for indicating therate of flow of a medium through an axial aperture of a cylindrical bodyand comprising: a rotation axis supported by said cylindrical body andbeing coaxial with it and further comprising: an impeller rotatablymounted on said cylindrical body and in communications with said medium,a cam member attached to said impeller and rotatable therewith, switchcontact means mounted opposite said cam member, said switch contactmeans being actuated by said cam member in accordance with the rotationof the impeller, an electrical power source for providing voltage foroperation of electrical circuitry through a common lead and through apower switch whose other terminal is connected to the other leadsupplying power to: a series connection of two resistors, one beingconnected with one end to said common terminal, second resistor beingconnected to said other lead, an n-p-n transistor having emitter, baseand collector electrodes, said collector electrode being connected tosaid other lead, said emitter electrode being connect to a resistorwhose Other end is connected to said common terminal, a capacitorconnected between the base electrode of said transistor and theinterconnection of said two in series connected resistors; said switchcontact means being connected across said capacitor (as shown in FIG. 1)providing drive current for said transistor whenever said switch contactmeans is closed, said drive current causes conduction of saidtransistor, thus producing a rectangular voltage pulses across saidresistor, a differentiator having its input lead connected tointerconnection of said resistor and said transistor for accepting saidrectangular voltage pulses across said resistor, having its common leadconnected to said common lead, and its output lead connected to a pulseseparation network input lead, allowing passage of differentiatingpulses of desired polarity (differentiating pulses representing apositve going and a negative going sharp pulse produced bydifferentiator per each rectangular voltage pulse), and having itscommon lead connected to said common lead, and its output lead connectedto the input lead of a means for producing rectangular pulses of sameamplitude and constant duration and same in number as the rectangularpulses produced by said transistor, having its common lead connected tosaid common lead, its supply lead connected to said other lead to acceptelectric power, and its output lead connected to the input lead of asquare wave amplifier having its common lead connected to said commonlead, its supply lead to said other lead to receive electric power foroperation and its output lead connected to the anode electrode of adiode having its cathode connected to an integrating capacitor havingits other plate connected to said common lead and used to integrate saidpulses of constant duration, first current limiting resistor tied up tothe interconnection of said diode and said capacitor, and its other endconnected to a pushbutton switch to allow fast discharge of saidintegrating capacitor through said first current limiting resistor andanother current limiting resistor connected to interconnection of saidfirst current limiting resistor and said pushbutton switch, acalibrating rheostat connected to said common lead and its other end tothe other end of said second current limiting resistor and a readoutmeans for providing a readout of the output of said integrating meansand having its other lead connected to said common lead.